Synergistic immunostimulatory effect of pidotimod and red ginseng acidic polysaccharide on humoral immunity of immunosuppressed mice

We investigated the synergistic effect of pidotimod and red ginseng acidic polysaccharide (RGAP) from Panax ginseng C.A. Meyer on humoral immune response challenged by lipopolysaccharide (LPS) and sheep red blood cells (SRBC) in immunosuppressed mice. Combined treatment with pidotimod and RGAP significantly increased the number of plaque-forming cells in the spleen in response to both LPS and SRBC, while treatment with either pidotimod or RGAP individually had no such effect. IgG levels in serum were augmented for secondary responses to SRBC in co-treated mice, but not in mice treated with either drug alone. Microscopic studies revealed that architecture of the spleen, thymus, and lymph nodes was conserved. GPT and creatinine in serum as indicators of hepatic and renal functions showed no difference compared to the control group. These results indicate that combined treatment with pidotimod and RGAP has an immunostimulatory effect in a synergistic manner on antibody response to challenge with LPS and SRBC without toxic changes.